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2003 chevy aveo #1 O2 sensor

Check engine light came on; checked at auto store and it indicated the #1 O2 sensor needs replacement. Which of the sensors is the #1, and how easy is it to replace?

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  • DemiGeek Mar 18, 2014

    Very helpful - thanks! Any thoughts on installation of the Bosch standard vs. universal upstream sensor? Price difference is huge, but may be worth it for less hassle.

  • Larry Blais
    Larry Blais Mar 18, 2014

    Thank you for writing back. The best way I can explain Direct fit VS. Universal is. With a direct fit, the installer just needs to remove the old sensor, apply a little never seez to the threads, and install the new sensor. With the universal type, the wiring is critical. The wiring chart must be followed to a tee and the connections (where the old wire meets the new wire) must be clean, tight, and protected. How confident are you with your wiring skills? Do you own and use a sodering gun? The connections must be well protected so the electrical signal doesn't fail or change do to moisture, corrosion, or abrasion. The entire length of the original needs to be mimiced when assembling the new sensor. It can be a little longer but not shorter. The O2 sensor harness should be routed the same way as the old one (take notes or pictures). The harness should be relaxed but not too much so that it could get damaged by a heat source or by abration. If your confident with your wiring skills then yes, go for it. Good luck with the repair, write back anytime.

  • Anonymous Mar 19, 2014

    Better yet codes have nothing to do with the need to install parts They are used to diagnose the system that set the MIL Lamp & see if you have a problem

  • Larry Blais
    Larry Blais Mar 19, 2014

    I agree that codes should be used as a diagnostic aid. Codes communicate that the ECU has identified a malfunction in a component, circuit, or related system. A professional technician would test and verify that the suspected failure was valid. If validation was not confirmed then they would test and confirm until the source was identified. If we are to help someone understand and improve their knowledge of diagnostics, repairing, testing, what tools are needed, proper maintenance, keeping records, terminology,and learn how to properly approach all potential repairs. We need to continuously improve on how we communicate to others. The better we listen, the better our responses will be. I think it is a bad habit to replace a part just because the code says it isn't working. But I disagree that codes have "nothing" to do with the need to install parts. I would rather say,"Codes represent the potential that a part may need to be replaced". In closing, I believe that there are too many variables to over simplify this subject. Sometimes a code will identify a failed component and sometimes a code will point out a failure, in a component that is being affected for an unknown reason. We need to continuously improve on how we communicate. The better we listen, the better our responses will be. Thank you.



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#1 is the up-stream sensor (The O2 sensor located before the Catalytic Convertor). #2 is the down-stream O2 sensor. This sensor is located after the Catalytic Convertor. I hope this helps, let me know if you have other questions concerning this issue. Good luck.

Posted on Mar 18, 2014

  • DemiGeek Mar 18, 2014

    Very helpful - thanks! Any thoughts on installation of the Bosch standard vs. universal sensor? Price difference is huge, but might be worth it if it saves some hassle.



Check Lights & Codes have nothing to do with replacing parts

You use the codes to diagnose the system with the fault

Google the code & read up

Posted on Mar 18, 2014

  • DemiGeek Mar 18, 2014

    Not a very helpful post. Per my posted question, the code had already been checked. Thanks anyway.



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You will need to use obd2 scanner to reset light after parts are replaced. It's the only way.

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SOURCE: check engine light on 2003 toyota tacoma, O2 sensor?

An O2 sensor code is a tricky one. It could mean SEVERAL different things, and I know how bad it sucks to hear this, but your best bet is to take it in and have a diagnostic ran on it at either a dealer or a good mechanic shop with a computer they can hook up to it. I had an "O2" code come up a while back on another car I used to have, and literally spent weeks and hundreds of dollars trying to fix it, and never did. Finally out of desperation took it in, paid the $90, and they found the problem and fixed it in like 30 minutes. Something I would have never even thought of was causing it (can't remember off the top of my head). After that I stopped wating time and money on check engine lights. One comes on in my car, I take it to have it ran for free at and auto parts store just to make sure it's not a loose gas cap or something, just to get an idea of what I'm looking at, then go and make an appointment to have to hooked up to a diagnostic computer to track down the problem. Good luck, and hope this helps save you some time and money.

Posted on Apr 05, 2010

Double One
  • 9 Answers

SOURCE: O2 sensor replacement

You'll find the sensors, they usually are found in pairs, located just before and just after the catalyctic converter, along the exhaust system. (Wear safety goggles to keep the dirt from getting in your eyes) With the car raised up on jack stands or on a hydraulic lift, (never use just a jack for support) look for the O2's, they look allot like spark plugs with a wire coming out of the visible end.Before ordering the parts, take a look and see what you need because with dual exhausts you may need as many as four and you might need to buy some anti-seize compound too but some sensors come pre-lubed, so wait 'til you see your parts prior to buying it. You may need your VIN to be certain you get the right parts. Sometimes, they can be hard to access and a special tool might be needed but if you are lucky an open end wrench will do the trick, keep this in mind when you locate yours on your car initially.The sensors come with a tip protector, leave it on until you are ready to install it and make sure not to contaminate the tip when inserting the tip in the opening. Also, be very careful to screw them in by hand, paying attention to the feel so as to avoid cross threading and then use the wrench to finish the job. With parts purchased, run the motor to heatup the exhaust manifold/pipes and git r dun, good luck. (Oh, almost forgot, mechanics gloves offer heat protection.)

Posted on Aug 24, 2012

Testimonial: "Thanks for your help charlie. changing that sensor wasn't too bad. Any good at a room lp fuse that keeps blowing immediately. I'm not sure exactly what is on that circuit. Been through a dozen fuses checking different things. But they keep popping right away. thanks again for your help. Robert"

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Please rate this answer. Thank you.

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